KR20080068754A - Multi-layered structure and manufacturing method thereof - Google Patents

Abstract

A multilayer structure having a layer made of an adhesive resin composition (A) and a layer made of another resin (B), wherein the adhesive resin composition (A) is made of boronic acid groups and boron-containing groups which can be converted into boronic acid groups in the presence of water. It consists of a thermoplastic resin (a1) containing at least one functional group selected from the group and a polyolefin (a2) not containing the functional group, wherein the blending weight ratio (a1 / a2) of the thermoplastic resin (a1) and the polyolefin (a2) is 1/99 to 15/85, a multilayer structure is described in which particles of the thermoplastic resin (a1) are dispersed in an average particle diameter of 0.1 to 1.2 mu m in a matrix made of polyolefin (a2). Accordingly, even when the content of the resin containing the special functional group in the adhesive resin composition layer is small, a multilayer structure having good interlayer adhesion is provided.

Multi-layered structure, adhesive resin composition, thermoplastic resin, polyolefin, blending weight ratio, interlayer adhesion

Description

Multilayer structure and process for producing same

The present invention relates to a multilayer structure having a layer made of an adhesive resin composition and a layer made of another resin, and a method of manufacturing the same.

Ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is excellent in gas barrier properties, oil resistance, steering resistance, and the like, and is used in various applications. On the other hand, however, EVOH has the drawback of high moisture permeability and high price. In order to compensate for its drawbacks while maintaining the excellent points of EVOH, EVOH is usually used in a lamination with thermoplastic resins such as polyolefin and polystyrene. However, since the adhesion between EVOH and such thermoplastic resin is poor, it is necessary to form an adhesive layer between both layers. As such an adhesive, modified polyolefins such as maleic anhydride modified polyolefin (polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc.) and ethylene-ethyl acrylate-maleic anhydride copolymer are widely used. However, when such an adhesive is used, adhesiveness may be inadequate depending on the brand of EVOH, and the interlayer adhesive force after coextrusion molding may change with time. On the other hand, resins containing at least one functional group selected from the group consisting of boronic acid groups and boron-containing groups that can be converted to boronic acid groups in the presence of water have very high reactivity with EVOH, and thus have the above problems when used as adhesives. I can eliminate it.

WO02 / 060961 (EP1369438A) discloses polystyrene and styrene-hydrogenated diene block copolymers containing in the side chain at least one functional group selected from the group consisting of boronic acid groups and boron-containing groups which can be converted to boronic acid groups in the presence of water. A multilayer structure using a resin composition as an adhesive and laminating an EVOH layer and a polyolefin layer through a layer made of the adhesive is described. And the multilayer structure obtained in this way was shown to have a good interlayer adhesiveness. It is described that the adhesive resin composition used here can be manufactured by melt-kneading the said styrene-hydrogenated diene block copolymer and polyolefin using a Banbury mixer, a twin screw extruder, etc. In the examples of this publication, the styrene-hydrogenated diene block copolymer and polyolefin are melt kneaded in advance using a twin screw extruder to obtain an adhesive resin composition, and then the obtained adhesive resin composition, polyolefin and EVOH are respectively It is fed to a single screw extruder and coextruded, and a multilayer structure is manufactured.

Since resins containing at least one functional group selected from the group consisting of boronic acid groups and boron-containing groups which can be converted to boronic acid groups in the presence of water are expensive, they are diluted with inexpensive polyolefins as described in the above publications. It is preferable to use it economically. However, depending on the application, the interlayer adhesion may be insufficient, and even when the amount of the resin containing such functional groups is small, it is strongly desired to obtain a multilayer structure having good interlayer adhesion.

Problems to be Solved by the Invention

This invention is made | formed in order to solve the said subject, and an object of this invention is to provide the multilayer structure which has favorable interlayer adhesive force even when there is little content of resin containing the special functional group in an adhesive resin composition layer. It is also an object to provide a suitable manufacturing method for obtaining such a multilayer structure.

Means to solve the problem

The problem is a multilayer structure having a layer made of an adhesive resin composition (A) and a layer made of another resin (B), wherein the adhesive resin composition (A) can be converted into boronic acid groups in the presence of boronic acid groups and water. It consists of the thermoplastic resin (a1) containing at least 1 sort (s) of functional group chosen from the group which contains a group, and the polyolefin (a2) which does not contain the said functional group, and the compounding weight ratio (a1 /) of thermoplastic resin (a1) and polyolefin (a2) solution by providing a multilayer structure characterized in that a2) is 1/99 to 15/85 and particles of thermoplastic resin (a1) are dispersed in an average particle diameter of 0.1 to 1.2 탆 in a matrix made of polyolefin (a2). do.

At this time, it is preferable that melt flow rate (190 degreeC, 2160g load) of a thermoplastic resin (a1) is 0.7-4g / 10min, and melt flow rate (190 degreeC, 2160g load) of polyolefin (a2) is 0.1- It is preferable that it is 10 g / 10 minutes. It is a suitable embodiment that another resin (B) is an ethylene-vinyl alcohol copolymer (B1), and the layer which consists of an ethylene-vinyl alcohol copolymer (B1), and the layer which consists of polyolefin (B2) is an adhesive resin composition ( It is more preferable that it is laminated | stacked through the layer which consists of A).

In addition, the above problem is to use a co-extrusion molding machine equipped with a plurality of extruders, the pellet of the thermoplastic resin (a1) and the pellet of the polyolefin (a2) is put into one extruder, the pellet of the other resin (B) in another extruder It is solved by providing a method for producing the multilayer structure, characterized in that by molding, by the coextrusion method. At this time, it is preferable to mix | blend a pellet of a thermoplastic resin (a1) and the pellet of a polyolefin (a2) beforehand, and to put into an extruder. The extruder into which the pellets of the thermoplastic resin (a1) and the pellets of the polyolefin (a2) are introduced is preferably a single screw extruder, and at this time, the linear velocity of the screw outer periphery in the single screw extruder is 0.8 to 8 m / min. More preferred.

Effects of the Invention

The multilayer structure of this invention has favorable interlayer adhesive force even when there is little content of resin containing the special functional group in an adhesive resin composition layer. Thereby, a multilayer structure can be provided which is inexpensive and has good interlayer adhesion. In addition, the multilayer structure described above can be easily obtained by the production method of the present invention.

Best Mode for Carrying Out the Invention

The adhesive resin composition (A) used in the multilayer structure of the present invention is referred to as at least one functional group (hereinafter sometimes referred to as boron-containing functional group) selected from the group consisting of boronic acid groups and boron-containing groups which can be converted into boronic acid groups in the presence of water. ) And a polyolefin (a2) containing no functional group.

First, the thermoplastic resin (a1) is demonstrated. The thermoplastic resin (a1) is characterized by containing at least one functional group selected from the group consisting of boronic acid groups and boron-containing groups which can be converted into boronic acid groups in the presence of water. Among the boron-containing functional groups, the boronic acid group is represented by the following formula (1).

In addition, the boron-containing group which can be converted into the boronic acid group in the presence of water refers to a boron-containing group that can be hydrolyzed in the presence of water and converted to the boronic acid group of the formula (I). More specifically, using water alone, a mixture of water and an organic solvent (toluene, xylene, acetone, etc.), a mixture of 5% aqueous boric acid solution and the organic solvent, and the like as a solvent, 10 minutes to 2 minutes under conditions of room temperature to 150 ℃ When hydrolyzed for a time, it means a functional group that can be converted to boronic acid groups. Representative examples of such functional groups include boronic acid ester groups represented by the following general formula (II), boronic anhydride groups represented by the following general formula (III), and boronic acid salt groups represented by the following general formula (IV).

Where

X ₁ and X ₂ are the same or different and each represents a hydrogen atom, an aliphatic hydrocarbon group (such as a straight or branched chain alkyl group having 1 to 20 carbon atoms, or an alkenyl group), an alicyclic hydrocarbon group (cycloalkyl group, cycloalkenyl group, etc.), And aromatic hydrocarbon groups (phenyl group, biphenyl group, etc.), wherein the aliphatic hydrocarbon group, alicyclic hydrocarbon group, and aromatic hydrocarbon group may have a substituent, and X ₁ and X ₂ may be bonded; X ₁ and X ₂ are not all hydrogen atoms,

R ₁ , R ₂ and R ₃ are the same hydrogen atom, aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group as those of X ₁ and X ₂ ,

M is an alkali metal.

Specific examples of the boronic acid ester group of formula (II) include boric acid dimethyl ester group, boronic acid diethyl ester group, boronic acid dipropyl ester group, boronic acid diisopropyl ester group, boronic acid dibutyl ester group, boronic acid dihexyl ester group, boronic acid di Cyclohexyl ester group, boronic acid ethylene glycol ester group, boronic acid propylene glycol ester group, boronic acid 1,3-propanediol ester group, boronic acid 1,3-butanediol ester group, boronic acid neopentyl glycol ester group, boronic acid A catechol ester group, a boronic acid glycerol ester group, a boronic acid trimethylol ethane ester group, a boronic acid trimethylol propane ester group, a boronic acid diethanolamine ester group, etc. are mentioned.

In addition, examples of the boronic acid salt groups of the general formula (IV) include alkali metal salt groups of boronic acid. Specifically, a sodium boron salt group, potassium boron salt group, etc. are mentioned.

Among such boron-containing functional groups, a boronic acid cyclic ester group is preferable from the viewpoint of thermal stability. As boronic acid cyclic ester group, the boronic acid cyclic ester group containing a 5-membered ring or a 6-membered ring is mentioned, for example. Specifically, a boronic acid ethylene glycol ester group, a boronic acid propylene glycol ester group, a boronic acid 1, 3- propanediol ester group, a boronic acid 1, 3- butanediol ester group, a boronic acid glycerin ester group, etc. are mentioned.

The thermoplastic resin (a1) may contain only one kind of boron-containing functional groups or may contain two or more kinds. The amount of the boron-containing functional group is preferably 0.0001 to 0.002 equivalents, that is, 100 to 2000 µeq / g, more preferably 150 to 1500 µeq / g, per 1 g of the thermoplastic resin (a1). If the amount of the functional group is less than 100 µeq / g, there is a fear that the interlayer adhesion of the obtained multilayer structure is lowered. Moreover, when the quantity of a functional group exceeds 2000 microeq / g, it will become easy to gelatinize and there exists a possibility that the external appearance of the obtained multilayer structure may deteriorate.

Although the coupling | bonding form of the boron containing functional group contained in the thermoplastic resin (a1) of this invention is not specifically limited, What is contained as a side chain of a polymer is suitable. By containing a boron containing functional group as a side chain, it is easy to enlarge content of a boron containing functional group.

In the case where the boron-containing functional group is bonded only to the terminal of the polymer, in particular, the amount of the functional group in the high molecular weight polymer may be relatively low, resulting in insufficient reactivity of the thermoplastic resin (a1). It may contain boron-containing functional groups at the side chains and at the ends.

Specific examples of the thermoplastic resin (a1) include polyethylene (ultra low density, low density, medium density, high density), ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, polypropylene, ethylene-propylene copolymer, ethylene and 1-butene Polyolefins such as copolymers with α-olefins such as isobutene, 3-methylpentene, 1-hexene and 1-octene; Graft modified substances such as maleic anhydride and glycidyl methacrylate of the polyolefin; Styrene resins such as polystyrene and styrene-acrylonitrile copolymers; Styrene-diene block copolymers such as styrene-butadiene block copolymer, styrene-isoprene copolymer, styrene-butadiene-styrene block copolymer and styrene-isoprene-styrene block copolymer; Styrene-hydrogenated diene block copolymers such as styrene-hydrogenated butadiene block copolymer, styrene-hydrogenated isoprene copolymer, styrene-hydrogenated butadiene-styrene block copolymer, styrene-hydrogenated isoprene-styrene block copolymer; (Meth) acrylic acid ester resins, such as polymethyl acrylate, polyethyl acrylate, and polymethyl methacrylate; Vinyl halide resins such as polyvinyl chloride and vinylidene fluoride; Semiaromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate; And aliphatic polyesters such as polyvalerolactone, polycaprolactone, polyethylene succinate, and polybutylene succinate. You may use only 1 type of these and may mix and use 2 or more types. Among them, polyolefins and styrene-hydrogenated diene block copolymers are preferred, and styrene-hydrogenated diene block copolymer resins are particularly preferred.

When the thermoplastic resin (a1) is a styrene-hydrogenated diene block copolymer, the weight ratio of the styrene unit and the hydrogenated diene unit contained in the copolymer resin is preferably 5/95 to 70/30, and 10/90 to 50/50 It is more preferable that is. When the said weight ratio is contained in this range, compatibility of a thermoplastic resin (a1) and a polyolefin (a2) becomes suitable and it becomes easy to include the average particle diameter of a thermoplastic resin (a1) in a preferable range. Moreover, when especially high interlayer adhesive force is desired, it is preferable that content of a styrene unit is small, and it is preferable that the weight ratio of a styrene unit and a hydrogenated diene unit is 30/70 or less specifically ,.

It is preferable that melt flow rate (190 degreeC, 2160g load) of a thermoplastic resin (a1) is 0.7-4 g / 10min. By including melt flow volume in such a range, the average particle diameter of the thermoplastic resin (a1) disperse | distributed in an adhesive resin composition (A) will fall easily in a preferable range. The melt flow rate is more preferably 1 g / 10 minutes or more, more preferably 1.5 g / 10 minutes or more. The melt flow rate is more preferably 3 g / 10 minutes or less, and more preferably 2.5 g / 10 minutes or less.

Next, the typical manufacturing method of the thermoplastic resin (a1) containing a boron containing functional group used for this invention is said.

1st method: The thermoplastic resin (a1) containing a boron containing functional group is a thermoplastic containing a boronic acid dialkyl ester group by reacting a borane complex and a boric acid trialkyl ester with a thermoplastic resin containing an olefinic double bond under a nitrogen atmosphere. After obtaining resin, it is obtained by making water or alcohol react as needed. In this way, the boron-containing functional group is introduced into the olefinic double bond of the thermoplastic resin by an addition reaction.

The olefinic double bond is introduced at the terminal by, for example, disproportionation occurring at the end of radical polymerization or in the main chain or side chain by side reaction during polymerization. In particular, the above-mentioned polyolefin is preferable in that an olefinic double bond can be easily introduced by pyrolysis or copolymerization of a diene compound under anoxic conditions, and the styrene-hydrogenated diene block copolymer is olefinic by controlling a hydrogenation reaction. It is preferable at the point which can couple | bond a double bond suitably.

It is preferable that it is 100-2000 microeq / g, and, as for content of the double bond of the thermoplastic resin used as a raw material, 200-1000 microeq / g is more preferable. By using such a raw material, it becomes easy to control the quantity of the boron containing functional group introduce | transduced. Moreover, control of the quantity of the olefinic double bond which remains after introduction can also be carried out simultaneously.

As the borane complex, borane-tetrahydrofuran complex, borane-dimethylsulfide complex, borane-pyridine complex, borane-trimethylamine complex, borane-triethylamine complex and the like are preferable. Among these, borane-dimethylsulfide complex, borane-trimethylamine complex, and borane-triethylamine complex are more preferable. The amount of the borane complex to be injected is preferably in the range of 1/3 to 10 equivalents relative to the olefinic double bond of the thermoplastic resin.

As boric acid trialkyl ester, the lower alkyl ester of boric acid, such as trimethyl borate, triethyl borate, tripropyl borate, and tributyl borate, is preferable. The amount of the boric acid trialkyl ester to be injected is preferably in the range of 1 to 100 equivalents relative to the olefinic double bond of the thermoplastic resin. Although it does not need to use a solvent in particular, When using, Saturated hydrocarbon solvent, such as hexane, heptane, octane, decane, dodecane, cyclohexane, ethylcyclohexane, decalin, is preferable. The reaction temperature is usually in the range of room temperature to 300 ° C, preferably 100 to 250 ° C, and at this temperature, the reaction is preferably carried out for 1 minute to 10 hours, preferably 5 minutes to 5 hours.

The boronic acid dialkyl ester group introduced into the thermoplastic resin by the above reaction can be hydrolyzed by a known method to form boronic acid groups. In addition, it is also possible to form any boronic acid ester group by transesterification with alcohols by a known method. Furthermore, dehydration condensation can be carried out by heating to form boronic anhydride groups. And also, it can be reacted with metal hydroxides or metal alcoholates by known methods to form boronate groups.

The conversion of such boron-containing functional groups is usually performed using organic solvents such as toluene, xylene, acetone, ethyl acetate and the like. Alcohols include monoalcohols such as methanol, ethanol and butanol; And polyhydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, neopentyl glycol, glycerin, trimethylol methane, pentaerythritol and dipentaerythritol. Examples of the metal hydroxides include hydroxides of alkali metals such as sodium and potassium. Examples of the metal alcoholate include those made of the above metals and the above alcohols. These things are not limited to what was illustrated. The amount of these to be used is usually 1 to 100 equivalents based on the boronic acid dialkyl ester group.

Second method: The thermoplastic resin (a1) containing a boron-containing functional group is a thermoplastic resin containing a known carboxyl group and amino group-containing boronic acid such as m-aminophenylbenzeneboronic acid and m-aminophenylboronic acid ethylene glycol ester, or An amino group containing boronic acid ester is obtained by amidation reaction by a well-known method. At this time, you may use condensing agents, such as carbodiimide. The boron-containing functional group introduced into the thermoplastic resin in this way can be converted to another boron-containing functional group by the above method.

As a thermoplastic resin containing a carboxyl group, Resin containing a carboxyl group in the terminal, such as a semi-aromatic polyester and an aliphatic polyester; Resin which introduce | transduced the monomeric unit which has carboxyl groups, such as acrylic acid, methacrylic acid, and maleic anhydride by copolymerization into polyolefin, styrene resin, (meth) acrylic acid ester resin, and vinyl halide type resin; Although the resin etc. which introduce | transduced maleic anhydride etc. by addition reaction to the thermoplastic resin containing said olefinic double bond are mentioned, It is not limited to these.

The polyolefin (a2) which comprises an adhesive resin composition (A) is a polyolefin which does not contain the said boron containing functional group. Specific examples thereof include polyethylene (ultra low density, low density, medium density, high density), ethylene-vinyl acetate copolymer, polypropylene, ethylene-polypropylene copolymer, and the like. In addition, graft modified products of polyolefin, maleic anhydride, glycidyl methacrylate, and the like can also be used. Among them, it is preferable to use an ethylene resin, and in particular, an ethylene resin having a low crystallization rate is preferably used in view of interlayer adhesion. Suitable examples of the ethylene resin having a slow crystallization rate include polyethylene having a density of 0.912 to 0.935 g / cm 3, and more preferably at most 0.930 g / cm 3. Examples of such polyethylenes include ultra low density polyethylene and low density polyethylene (including LLDPE), and a plurality of polyethylenes may be mixed to adjust the density. In addition, another suitable example of the ethylene resin having a slow crystallization rate is exemplified by ethylene-vinyl acetate copolymer, and the density thereof is suitably 0.94 to 0.98 g / cm 3, more preferably 0.96 g / cm 3 or less. Moreover, as polyolefin (a2), you may mix and use the scrap of the multilayered structure of this invention in the range which does not inhibit the objective of this invention.

It is preferable that melt flow rate (190 degreeC, 2160g load) of polyolefin (a2) is 0.1-10g / 10min. By including melt flow rate in such a range, it can be easily coextruded and the average particle diameter of the thermoplastic resin (a1) disperse | distributed in an adhesive resin composition (A) becomes easy to enter in a preferable range. The melt flow rate is more preferably 0.5 g / 10 minutes or more, more preferably 1 g / 10 minutes or more. The melt flow rate is more preferably 5 g / 10 minutes or less.

Adhesive resin composition (A) consists of a thermoplastic resin (a1) and a polyolefin (a2). The blending weight ratio (a1 / a2) of the thermoplastic resin (a1) to the polyolefin (a2) is 1/99 to 15/85, and the adhesive resin composition (A) used in the present invention comprises a relatively small amount of thermoplastic resin (a1). By blending, good interlayer adhesion can be obtained. When the blending weight ratio a1 / a2 is less than 1/99, the interlayer adhesion is insufficient. The compounding weight ratio (a1 / a2) is preferably 1.5 / 98.5 or more, more preferably 1.75 / 98.25 or more. On the other hand, when compounding weight ratio (a1 / a2) exceeds 15/85, moldability will fall and manufacturing cost will rise. The blending weight ratio (a1 / a2) is preferably 10/90 or less, more preferably 5/95 or less.

You may mix | blend an antioxidant, a plasticizer, a heat stabilizer, a ultraviolet absorber, an antistatic agent, a lubricating agent, a coloring agent, a filler, or another resin with respect to an adhesive resin composition (A) in the range in which the effect of this invention is not impaired.

An adhesive resin composition (A) consists of a thermoplastic resin (a1) and a polyolefin (a2), and can be obtained by melt-kneading both. The method of melt kneading the thermoplastic resin (a1) and the polyolefin (a2) is not particularly limited, but melt kneading under conditions that can disperse the particles of the thermoplastic resin (a1) to a specific particle diameter in a matrix composed of the polyolefin (a2) It is important. As will be described in detail below, by having such a specific average particle diameter, a multilayer structure having excellent interlayer adhesion can be obtained.

In general, when a plurality of resin raw materials are mixed to produce a resin composition, it is considered that mixing is sufficiently uniform. Therefore, in many cases, mixing is carried out using a mixing device having a high kneading capacity such as a twin screw extruder so as to achieve the finest particle diameter possible. Surprisingly, however, in the adhesive resin composition (A) used in the present invention, when the dispersed particle diameter becomes too small, it has become apparent that the interlayer adhesive force is lowered. Although the reason is not necessarily clear, it may be because the quantity of the boron containing functional group which exists in the interface of an adhesive resin composition (A) layer and another resin (B) layer changes with dispersion particle diameter. On the other hand, when dispersion particle diameter is too big | large, since stain | seat tends to generate | occur | produce in an adhesive resin composition (A) layer, also, interlayer adhesive force falls again. Consequently, in order to obtain good interlayer adhesion, it is extremely important to adjust the particle diameter of the thermoplastic resin (a1) in the adhesive resin composition (A) layer to a specific range.

Therefore, the method of melt-kneading the thermoplastic resin (a1) and the polyolefin (a2) in advance to produce pellets of the adhesive resin composition (A), and then supplying the obtained pellets to a molding machine to form a multilayer structure is excessively kneaded. It is often unfavorable. On the contrary, it is preferable to melt-knead the thermoplastic resin (a1) and the polyolefin (a2) only once when molding the multilayer structure in view of the interlayer adhesiveness. This point is also preferable in terms of manufacturing cost, and the manufacturing cost of the multilayer structure is reduced by eliminating the melt kneading operation once. In addition, although the thermoplastic resin (a1) has a highly reactive boron-containing functional group, the melt stability of the functional group is not necessarily good and may cause crosslinking or decomposition of the resin, and as a result, the interlayer adhesion in the resulting multilayer structure. There is a fear that problems such as deterioration, coloring, fish eye, appearance defects such as vertical lines, odor generation due to decomposition gas, and the like may occur.

The method of molding the multilayer structure is not particularly limited, but for example, in addition to the method of coextrusion molding the adhesive resin composition (A) and the other resin (B), construction molding, extrusion coating, dry lamination, solution coating, and the like A known method of is employed. Among these, coextrusion molding and construction extrusion molding are suitable, and coextrusion molding is especially suitable. In the case of employing co-extrusion, the melt-extruded layer components may be brought into contact with each other in a die for lamination (in-die lamination method), or may be contacted outside of the die for lamination (out-die lamination method). At this time, by performing a contact under pressure, the adhesiveness of each layer of a multilayer structure can be improved. As pressure, the range of 1-500Kg / cm <2> is preferable. Hereinafter, although co-extrusion shaping | molding is demonstrated as an example, it is the same also in the case of co-extrusion shaping instead of co-extrusion shaping | molding.

In the case of coextrusion molding, a coextrusion molding machine equipped with a plurality of extruders is used, a pellet of thermoplastic resin (a1) and a pellet of polyolefin (a2) are charged into one extruder, and the other extruder (B) The method of inserting a pellet and shaping | molding by co-extrusion method is suitable. At this time, it is suitable to mix | blend a pellet of a thermoplastic resin (a1) and the pellet of a polyolefin (a2) beforehand, and to put into one extruder of a coextrusion molding machine. Although the method of dry blending is not specifically limited, In order to uniformly dry mix, it is preferable to fully mechanically mix the pellet of a thermoplastic resin (a1) and the pellet of a polyolefin (a2). Specifically, the pellets of the thermoplastic resin (a1) and the pellets of the polyolefin (a2) are continuously weighed and mixed, and then a predetermined amount of the thermoplastic resin (a tumbler or the like) is used in advance using a feeder that continuously feeds the extruder ( The method of mixing the pellet of a1) and the pellet of polyolefin (a2), and then supplying it to an extruder etc. is illustrated as a suitable method.

In order to prevent excess kneading, it is preferable that the extruder into which the pellet of a thermoplastic resin (a1) and the pellet of a polyolefin (a2) is thrown in is a single screw extruder. It is suitable to melt knead only once with a single screw extruder and to obtain a molded article directly. Although the structure of the single screw extruder used here is not specifically limited, L / D is 5-50 normally, Preferably it is 10-50. In addition, it is preferable to make melt-kneading temperature into the temperature which resin melt does not deteriorate suitably, and melt viscosity falls suitably, Preferably it is 180-280 degreeC, More preferably, it is 200-250 degreeC. If the residence time in the extruder is too short, there is a fear that a uniform composition cannot be obtained. On the contrary, if the residence time is too long, the resin may deteriorate. Therefore, the residence time in the extruder is suitably 1 to 30 minutes, more preferably 2 to 30 minutes.

When melt kneading with a single screw extruder, if the shear rate is too high, the particle diameter of the thermoplastic resin (a1) in the adhesive resin composition (A) obtained is too small, and if the shear rate is too low, the adhesive resin composition (A obtained The particle diameter of the thermoplastic resin (a1) in) becomes too large. Therefore, it is important to adjust the shear rate at the time of melt-kneading with a single screw extruder to an appropriate range. Specifically, it is suitable that the linear velocity of the screw outer periphery in a single screw extruder is 0.8 to 8 m / min. Here, the linear velocity (m / min) of the screw outer circumference is a value calculated by multiplying the diameter of the screw by the circumference and the rotational speed, and is a value correlated with the shear rate inside the extruder. When the linear velocity of a screw outer periphery is less than 0.8 m / min, there exists a possibility that a dispersion particle diameter may become large too much, More preferably, it is 1.2 m / min or more, More preferably, it is 1.5 m / min or more. On the other hand, when the linear velocity of a screw outer periphery exceeds 8 m / min, there exists a possibility that a dispersed particle diameter may become too small, More preferably, it is 6 m / min or less, More preferably, it is 4 m / min or less.

In the multilayer structure of the present invention, in the adhesive resin composition (A) layer, it is important that the particles of the thermoplastic resin (a1) are dispersed at an average particle diameter of 0.1 to 1.2 mu m in the matrix made of the polyolefin (a2). By being dispersed at such an average particle diameter, excellent interlayer adhesion can be obtained. Here, the said average particle diameter is an arithmetic mean value obtained by measuring the short diameter and long diameter of the particle | grains observed in the cross section obtained by cutting | disconnecting a multilayer structure in the direction perpendicular | vertical to an extrusion direction (or the injection direction), and averaging them. An observation place is the vicinity of the interface between an adhesive resin composition (A) layer and another resin (B) layer.

When the average particle diameter is 0.1 µm or less, the interlayer adhesion is lowered. The average particle diameter is suitably 0.12 micrometers or more, More preferably, it is 0.14 micrometers or more. On the other hand, when an average particle diameter exceeds 1.2 micrometers, also an interlayer adhesive force falls. The average particle diameter is suitably 1 µm or less, more preferably 0.8 µm or less. Thus, it became clear that good interlaminar adhesion was obtained within the range of extremely limited particle diameters.

The multilayer structure of the present invention has a layer made of an adhesive resin composition (A) and a layer made of another resin (B). Examples of the other resin (B) include, but are not particularly limited to, polyethylene (ultra low density, low density, medium density, high density), ethylene-vinyl acetate copolymer, EVOH, ethylene-acrylic acid ester copolymer, polypropylene, ethylene-propylene copolymer, and the like. Polyolefins; Graft modified products of the polyolefin with maleic anhydride, glycidyl methacrylate, and the like; Semiaromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate; Aliphatic polyesters such as polyvalerolactone, polycaprolactone, polyethylene succinate and polybutylene succinate; Aliphatic polyamides such as polycaprolactam, polylaurolactam, polyhexamethylene azipamide, and polyhexamethylene azelamide; Polyethers such as polyethylene glycol and polyphenylene ether; Polycarbonate; Styrene-based polymers such as polystyrene and styrene-acrylonitrile-butadiene copolymers; Polymethyl methacrylate; Resin, such as vinyl halide type polymers, such as polyvinyl chloride and vinylidene fluoride, is mentioned. Such resin may be used independently and may be used in mixture of 2 or more types. Moreover, you may mix and use the scrap of the multilayered structure of this invention with another resin (B) in the range in which the objective of this invention is not impaired.

Among the above-mentioned resins, EVOH (B1) is particularly preferable as another resin (B). Although the ethylene content of EVOH (B1) is not specifically limited, It is preferable that it is 3-70 mol%. When ethylene content is less than 3 mol%, there exists a possibility that melt stability may become inadequate, More preferably, it is 5 mol% or more, More preferably, it is 20 mol% or more. On the other hand, when ethylene content exceeds 70 mol%, there exists a possibility that blocking property may become inadequate, More preferably, it is 60 mol% or less, More preferably, it is 50 mol% or less. In addition, the saponification degree of EVOH (B1) is usually 10 to 100 mol%, preferably 50 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 95 to 100 mol%, most preferably 99 to 100 mol% desirable. If the degree of saponification is low, the crystallinity of EVOH (B1) may be insufficient, or the thermal stability during melt molding may become insufficient.

EVOH (B1) can be prepared by a known method of copolymerizing ethylene and vinyl esters using a radical initiator and then saponifying in the presence of an alkali catalyst. Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl caprate, and vinyl benzoate. You may use 1 type in such vinyl ester, and may mix and use 2 or more types. Among these, vinyl acetate is preferable.

Under the present circumstances, you may copolymerize and copolymerize another copolymerization component in the range which does not inhibit the objective of this invention. Other components herein include olefinic monomers such as propylene, 1-butene and isobutene; Acrylamide monomers such as acrylamide, N-methylacrylamide, N-ethylacrylamide, and N, N-dimethylacrylamide; Methacrylamide monomers such as methacrylamide, N-methyl methacrylamide, N-ethylacrylamide, and N, N-dimethylmethacrylamide; Vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, t-butyl vinyl ether and dodecyl vinyl ether; Allyl alcohol; Vinyltrimethoxysilane; N-vinyl-2-pyrrolidone, etc. are mentioned.

EVOH (B1) obtained in this way may be used independently, and may be used in mixture with other EVOH (B1) differing in ethylene content, saponification degree, polymerization degree, etc. Moreover, you may add and use thermoplastic resins other than EVOH (B1) in the range in which the objective of this invention is not impaired. The content of the thermoplastic resin in EVOH (B1) is preferably in the range of 0 to 50% by weight, more preferably in the range of 0 to 40% by weight, still more preferably in the range of 0 to 10% by weight.

A suitable layer structure of the multilayer structure is one in which a layer made of EVOH (B1) and a layer made of hydrophobic thermoplastic resin are laminated through a layer made of adhesive resin composition (A). This is a configuration that compensates for the disadvantages of high moisture permeability and high cost of EVOH (B1). As such a hydrophobic thermoplastic resin, polyolefin (B2), a styrene polymer, polyester, etc. are illustrated. Among them, particularly preferred embodiments are those in which a layer made of an ethylene-vinyl alcohol copolymer (B1) and a layer made of a polyolefin (B2) are laminated through a layer made of an adhesive resin composition (A).

As a layer structure of the multilayer structure of this invention, the following are mentioned as a suitable example. Here, A represents an adhesive resin composition, B1 represents EVOH, B2 represents a hydrophobic thermoplastic resin represented by polyolefin, and Reg represents a resin layer containing scrap of the multilayer structure. B2 may be composed of a plurality of layers. The thickness of each layer of the multilayer structure can be arbitrarily selected, and by this selection, it is possible to make the thickness of the whole multilayer structure into a desired range.

2nd floor: A / B1

3rd floor: B1 / A / B2

4th floor: B1 / A / Reg / B2

5th floor: B2 / A / B1 / A / B2, B2 / A / B1 / A / Reg,

     B1 / A / B2 / Reg / B2

6th floor: B2 / Reg / A / B1 / A / B2

7th floor: B2 / Reg / A / B1 / A / Reg / B2

The multilayer structure obtained in this way is excellent in interlayer adhesion, as is apparent from the examples described later. Moreover, even when it is collect | recovered and can be reused again, occurrence of the abnormality of an external appearance, such as a surface disorder, a gel, butt, is few. The multilayer structure can also be used for stretching operations such as uniaxial stretching, biaxial stretching, blow stretching, thermoforming operations such as vacuum press forming, and the like. It can also be processed into molded products such as films, sheets, bottles, and cups with excellent mechanical properties and gas barrier properties. The molded article obtained is useful for applications requiring gas barrier properties such as food packaging, medical (medical and medical device) packaging materials, fuel tanks, and the like.

Hereinafter, although an Example etc. demonstrate this invention further in detail, this invention is not limited at all by these. In addition, unless otherwise indicated in the following description, a ratio means a weight ratio and "%" means "weight%." The average particle diameter of the thermoplastic resin (a1) was measured by the following method.

Method of measuring average particle diameter

The multilayer sheet was cut | disconnected in the direction perpendicular | vertical to an extrusion direction, the cross section of the adhesive resin composition (A) layer was image | photographed 30,000 times with the transmission electron microscope, and the structure of the adhesive resin composition (A) layer was observed. The threshold value was set such that the main particles could be recognized as particles and the background was not black and continuous, and the photographed image was black and white binarized. In the binarized image, the long and short diameters of all particles contained in a square area of 1.6 mu m x 1.6 mu m including the interface between the adhesive resin composition (A) layer and the EVOH (B1) layer were measured, and The total average was taken as the average particle diameter. At this time, the dot of 0.0005 micrometers or less which is indistinguishable from the shade of a screen is not made into measurement object.

Synthesis Example 1 [Synthesis of boronic acid ester group-containing SEBS (X-1)]

Styrene-hydrogenated butadiene-styrene block copolymer (SEBS, styrene / hydrogenated butadiene = 16/84 (weight ratio), 94% hydrogenation rate in butadiene units, double bond amount 960μeq / g, melt flow rate 5g / 10min (230 ° C, 2160 g load)) was fed to the twin screw extruder at a rate of 7 kg / hr while replacing the inlet with 1 L / min of nitrogen. Next, from Liquid Feeder 1, a mixture of borane-triethylamine complex (TEAB) and boric acid 1,3-butanediol ester acid (BBD) (TEAB / BBD = 29/71, weight ratio) was added at a rate of 0.6 kg / hr. 1,3-butanediol was supplied from the liquid feeder 2 at a rate of 0.4 kg / hr, and kneaded continuously. During kneading the pressure was adjusted such that the gauges of Vent 1 and Vent 2 showed about 20 mm Hg. As a result, SEBS (X-1) containing boronic acid 1,3-butanediol ester group (BBDE) was obtained at a rate of 7 kg / hr from the outlet. The boronic acid 1,3-butanediol ester group content of the SEBS was 650 µeq / g, the double bond amount was 115 µeq / g, and the melt flow rate was 1.6 g / 10 minutes (190 ° C, 2160 g load).

The structure and operating conditions of the twin screw extruder used for the above reaction are as follows.

Co-Directional Twin Screw Extruder TEM-35B [Reference: Toshibagikai Co., Ltd.]

Screw diameter: 37mmφ

L / D: 52 (15 blocks)

Liquid feeder: C3 (liquid feeder 1), C11 (liquid feeder 2)

Vent position: C6 (Bent 1), C14 (Bent 2)

Screw configuration: Sealing is used between C5-C6, C10-C11 and C12.

Cylinder set temperature: C1 (water cooling), C2 to C3 (200 ° C), C4 to C15 (250 ° C), die (250 ° C)

Screw speed: 400rpm

Synthesis Example 2 [Synthesis of boronic acid ester group-containing SEBS (X-2)]

Styrene / hydrogenated butadiene = 16/84 (weight ratio) in the synthesis example 1, styrene-butadiene unit hydrogenation rate 94%, double bond amount 960 microeq / g, melt flow rate 3 g / 10 minutes (230 degreeC, 2160 g load) SEBS (X-2) containing boronic acid 1,3-butanediol ester group (BBDE) was synthesize | combined similarly to the synthesis example 1 except having used the hydrogenated butadiene-styrene block copolymer. The boronic acid 1,3-butanediol ester group content of SEBS (X-2) was 650 μeq / g, the double bond amount was 115 μeq / g, and the melt flow rate was 0.6 g / 10 min (190 ° C., 2160 g load).

Example 1

Pellets of SEBS (X-1) obtained in Synthesis Example 1 and linear low density polyethylene (LLDPE) "ULTZEX 2022L" manufactured by Mitsui Chemical Co., Ltd. (melting flow rate 2.1 g / 10 min: 190 ° C, 2160 g load, density 0.919 g / cm 3) of pellets were dry blended using a tumbler at a weight ratio of 4/96 to obtain a mixture of two pellets of cattle.

Next, high-density polyethylene (HDPE) "LF443" manufactured by Nippon Polyethylene Co., Ltd. (melting flow rate 1.5g / 10min: 190 ° C, 2160g load), the pellet mixture, EVOH "F171B" manufactured by Kuraray Co., Ltd. Ethylene content 32 mol%) as a raw material, each introduced into a separate extruder, and according to the conditions shown below, three kinds of five layers of HDPE / adhesive resin composition (A) / EVOH / adhesive resin composition (A) / HDPE Multilayer sheets were prepared by coextrusion molding. The thickness structure of the obtained multilayer sheet was 50/10/10/10/50 micrometers.

The configuration and operating conditions of the coextrusion molding machine are as follows.

Extruder 1 [HDPE (B2)]:

Equipment: GT-32-A type single screw extruder manufactured by Kogaku Kenkyu Sho Plastic Co., Ltd.

Screw diameter: 32mmφ

Screw speed: 62rpm

Cylinder set temperature: 220 ℃

Extruder 2 [adhesive resin composition (A)]:

Apparatus: Single screw extruder `` P25-18AC '' manufactured by Osaka Seiki Kosaku Co., Ltd.

Screw diameter: 25mmφ

Screw configuration: fullflight

L / D: 18

Screw speed: 30rpm

Linear velocity of screw periphery: 2.36 m / min

Cylinder set temperature: 220 ℃

Emission: approx. 1 kg / hr

Retention time in the extruder: about 9 minutes

Residence time in the die: about 2 minutes

Extruder 3 [EVOH (B1)]:

Equipment: Single screw extruder `` LaboME type CO-NXT '' manufactured by Toyo Seiki Sesakusho

Screw diameter: 20mmφ

Screw speed: 18rpm

Cylinder set temperature: 220 ℃

Die size: 300mm

Sheet take-up speed: 4m / min

Cooling roll temperature: 50 ℃

Immediately after sheet production, the T-type peel strength at the interface between the adhesive resin composition (A) layer and the EVOH (B1) layer of the obtained multilayer sheet was autographed under conditions of 65% RH at 20 ° C (tension rate 250 mm / min). Was measured and the obtained value was defined as interlayer adhesion. The interlayer adhesion was 1650 g / 15 mm. Moreover, the multilayer sheet was cut | disconnected in the direction perpendicular | vertical to an extrusion direction, the cross section of the adhesive resin composition (A) layer was image | photographed 30,000 times with the transmission electron microscope, and the structure of the adhesive resin composition (A) layer was observed. In the adhesive resin composition (A) layer, particles of SEBS (X-1) were dispersed in a matrix made of LLDPE. According to the method described above, the average particle diameter of the thermoplastic resin (a1) was measured, and the average particle diameter was 0.2 탆.

Example 2

A multilayer structure was obtained in the same manner as in Example 1 except that SEBS (X-2) obtained in Synthesis Example 2 was used instead of SEBS (X-1) in Example 1. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Example 3

The rotation speed of the extruder 2 which introduce | transduces adhesive resin composition (A) in Example 1 was increased to 1.6 times (48 rpm), and the linear velocity of the screw outer periphery was adjusted to 3.77 m / min. At this time, the rotation speed of the extruders 1 and 2 was also increased to 1.6 times, and the sheet taking-out speed was also adjusted to 1.6 times. A multilayer sheet having the same thickness configuration as that of Example 1 was obtained in the same manner as in Example 1 except for this point. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Example 4

Low Density Polyethylene (LDPE) "Suntec L2340" manufactured by Asahi Chemical Co., Ltd. instead of the linear low density polyethylene (LLDPE) dry-blended in Example 1 (melting flow rate 3.8g / 10min: 190 degreeC, 2160g load, A multilayer sheet was obtained in the same manner as in Example 1 except that the density of 0.923 g / cm 3) was used. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Example 5

Mitsui DuPont Co., Ltd. ethylene-vinyl acetate copolymer resin (EVAc) "EV360" (melting flow rate 2.0g / 10min: 190 degreeC, 2160g load) instead of the linear low density polyethylene (LLDPE) dry-blended in Example 1, A multilayer sheet was obtained in the same manner as in Example 1 except that the density of 0.950 g / cm 3) was used. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Example 6

Instead of the linear low density polyethylene (LLDPE) arranged in the outer layer of the multilayer sheet in Example 1, polypropylene (PP) "EG7F" manufactured by Nippon Polypropylene Co., Ltd. (melting flow rate 1.3 g / 10 min: 190 ° C, 2160 g) A multilayer sheet was obtained in the same manner as in Example 1 except for using a load). The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Example 7

A multilayer sheet was obtained in the same manner as in Example 1 except that the blending weight ratio of SEBS (X-1) and linear low density polyethylene (LLDPE) was 2/98 in Example 1. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Comparative Example 1

Instead of introducing the mixture of pellets into the extruder 2 in Example 1, the multilayer sheet was obtained like Example 1 except having introduced the pellet of the resin composition obtained by melt-kneading previously by the twin screw extruder. The result evaluated similarly to Example 1 is put together in Table 1, and is described. The configuration and operating conditions of the twin screw extruder used for melt kneading are as follows.

Coaxial twin-screw extruder Laplast Mill (manufactured by Toyo Seiki Sesaku Sho)

Soccer Castle: 2 Axis East

Screw diameter: 25mmφ

L / D: 25

Cylinder set temperature: 220 ℃

Screw speed: 150rpm

Linear velocity of screw periphery: 11.78 m / min

Supply balance: 5 kg / hr

Retention time: 2 minutes

Comparative Example 2

A multilayer sheet was obtained in the same manner as in Example 1 except that the blending weight ratio of SEBS (X-1) and linear low density polyethylene (LLDPE) was 0.5 / 99.5. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Comparative Example 3

The rotation speed of the extruder 2 which introduce | transduces an adhesive resin composition (A) in Example 1 was 3.73 times (112 rpm), and the linear velocity of the screw outer periphery was 8.80 m / min. At this time, the rotation speed of the extruder 1 was increased to 1.87 times, the rotation speed of the extruder 2 was increased to 3.73 times, and the sheet take-up speed was adjusted to 3.73 times. Except such a point, it carried out similarly to Example 1, and multi-layer of three types 5 layers of HDPE / adhesive resin composition (A) / EVOH / adhesive resin composition (A) / HDPE = 25/10/10/10/25 µm The sheet was prepared by coextrusion molding. The result of having evaluated the obtained multilayer sheet similarly to Example 1 is put together in Table 1, and is described.

Comparative Example 4

The rotation speed of the extruder 2 which introduce | transduces an adhesive resin composition (A) in Example 1 was 0.33 times (10 rpm), and the linear velocity of the screw outer periphery was 0.79 m / min. At this time, the rotation speed of the extruders 1 and 2 was also increased to 0.33 times, and the sheet taking-out speed was also adjusted to 0.33 times. A multilayer sheet having the same thickness configuration as that of Example 1 was obtained in the same manner as in Example 1 except for this point. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Comparative Example 5

Low Density Polyethylene (LDPE) manufactured by Asahi Chemical Co., Ltd., `` Santek L2340 '' instead of linear low density polyethylene (LLDPE) melt kneaded in Comparative Example 1 (melt flow rate 3.8 g / 10 min: 190 ° C, 2160 g load, A multilayer sheet was obtained in the same manner as in Comparative Example 1 except that the density of 0.923 g / cm 3) was used. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Comparative Example 6

Mitsui DuPont Co., Ltd. ethylene-vinyl acetate copolymer resin (EVAc) "EV360" (melting flow rate 2.0g / 10min: 190 degreeC, 2160g load) instead of the linear low density polyethylene (LLDPE) melt-kneaded in the comparative example 1 A multilayer sheet was obtained in the same manner as in Comparative Example 1 except that the density of 0.950 g / cm 3) was used. The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Comparative Example 7

Instead of linear low density polyethylene (LLDPE) arranged in the outer layer of the multilayer sheet in Comparative Example 1, polypropylene (PP) "EG7F" manufactured by Nippon Polypropylene Co., Ltd. (melting flow rate 1.3 g / 10 min: 190 ° C, 2160 g) A multilayer sheet was obtained in the same manner as in Comparative Example 1 except for using a load). The result evaluated similarly to Example 1 is put together in Table 1, and is described.

Example 8

Pellets of SEBS (X-1) obtained in Synthesis Example 1, and low density polyethylene (LDPE) `` MIRASON 102 '' manufactured by Mitsui Chemical Co., Ltd. (melting flow rate 0.35 g / 10 min: 190 ° C, 2160 g load, density 0.919) g / cm 3) of the pellets were dry blended using a tumbler at a weight ratio of 10/90 to obtain a mixture of both pellets.

Next, Mitsui Chemical Co., Ltd. low density polyethylene (LDPE) "MIRASON 102" (melting flow rate 0.35 g / 10 minutes: 190 ° C, 2160 g load), the pellet mixture, EVOH "F171B manufactured by Kuraray Co., Ltd. (32 mol% of ethylene) as a raw material, and using LDPE / adhesive resin composition (A) / EVOH / adhesion using four kinds of seven-layer blow molding machines `` TB-ST-6P '' manufactured by Sugenki Kogyo Co., Ltd. Three types of five-layered direct blow bottles (average thickness in the trunk part of a direct blow bottle: 340/40/40/40/340 micrometer) of the resin composition (A) / LDPE were shape | molded. At this time, the extruder temperature of LDPE was 220 degreeC, the extruder temperature of adhesive resin composition (A) was 210 degreeC, the extruder temperature of EVOH was 210 degreeC, the resin temperature in die | dye was 220 degreeC, and the die temperature was 40 degreeC. The average particle diameter measured in the same manner as in Example 1 was 0.5 µm. The obtained direct blow bottle was filled with water as the contents and tightly sealed under normal pressure, and then placed on a 20 cm-long triangle pedestal having an angle of 90 ° from a height of 50 cm in a state where the bottle body was leveled. Although the corners were naturally dropped so as to fit in the center of the bottle body part, it was confirmed that there was no occurrence of interlaminar peeling and a performance that satisfies the demand was obtained.

The structure and operating conditions of the extruder used for molding are as follows.

Apparatus: Four 7-layer direct blow molding machines manufactured by Suzuki Teksho.

Single screw extruder 1 (HDPE):

Screw diameter: 45mmφ

Screw speed: 20 rpm

Cylinder set temperature: 200 ℃

Single screw extruder 2 (HDPE):

Screw diameter: 40mmφ

Screw speed: 17 rpm

Cylinder set temperature: 200 ℃

Single screw extruder 3 (adhesive resin composition (A))

Screw diameter: 35mmφ

Screw configuration: full flight

L / D: 23

Screw speed: 11 rpm

Cylinder set temperature: 200 ℃

Discharge: 0.7 kg / hr

Retention time in the extruder: about 10 minutes

Single screw extruder 4 (EVOH):

Screw diameter: 35mmφ

Screw speed: 5.3rpm

Cylinder set temperature: 210 ℃

As apparent from Table 1, in Examples 1 to 7 in which the average particle diameter of the thermoplastic resin (a1) was in the range of 0.1 to 1.2 µm, good interlayer adhesion was obtained. On the contrary, in Comparative Examples 1, 5, 6, and 7, which were melt-kneaded in advance with a twin-screw extruder to produce pellets of the adhesive resin composition (A), the average particle diameter was less than 0.1 µm and the interlayer adhesion was It was greatly reduced. Moreover, also in the comparative example 3 in which the linear velocity of the screw outer periphery of an extruder is high, the average particle diameter became less than 0.1 micrometer and the interlayer adhesive force fell significantly. On the other hand, in the comparative example 4 in which the linear velocity of the screw outer periphery of an extruder was low, an average particle diameter exceeded 1.2 micrometers, and also the interlayer adhesive force fell significantly. That is, it became clear that even if the average particle diameter of the thermoplastic resin (a1) was too large or too small, the interlayer adhesive force was greatly lowered, and the interlayer adhesive force was good when it had a specific average particle diameter. Moreover, the interlayer adhesive force in Example 7 whose compounding weight ratio (a1 / a2) of thermoplastic resin (a1) and polyolefin (a2) is 2/98 is 1530g / 15mm, and compounding weight ratio (a1 / a2) is 4/96. It is only slightly lower than the interlayer adhesion (1650 g / 15 mm) in Example 1. On the contrary, in the comparative example 2 whose compounding weight ratio (a1 / a2) is 0.5 / 99.5, it turns out that the interlayer adhesive force is only 100g / 15mm and it fell large. That is, it can be seen that the interlayer adhesive strength is remarkably changed at the blending weight ratio (a1 / a2) 0.5 / 99.5 to 2/98, and the interlayer adhesive strength is greatly improved even by blending a small amount of the thermoplastic resin (a1).

Claims (9)

A multilayer structure having a layer made of an adhesive resin composition (A) and a layer made of another resin (B), The adhesive resin composition (A) is a thermoplastic resin (a1) containing at least one functional group selected from the group consisting of boronic acid groups and boron-containing groups which can be converted into boronic acid groups in the presence of water and polyolefins containing no such functional groups. (a2), wherein the compounding weight ratio (a1 / a2) of the thermoplastic resin (a1) and the polyolefin (a2) is 1/99 to 15/85, and the particles of the thermoplastic resin (a1) in the matrix composed of the polyolefin (a2) Is dispersed in an average particle diameter of 0.1 to 1.2 mu m. The multilayer structure according to claim 1, wherein a melt flow rate (190 ° C., 2160 g load) of the thermoplastic resin (a1) is 0.7 to 4 g / 10 minutes. The multilayer structure according to claim 1 or 2, wherein the melt flow rate (190 ° C., 2160 g load) of the polyolefin (a2) is 0.1 to 10 g / 10 minutes. The multilayer structure according to any one of claims 1 to 3, wherein the other resin (B) is an ethylene-vinyl alcohol copolymer (B1). The multilayer structure according to claim 4, wherein a layer made of an ethylene-vinyl alcohol copolymer (B1) and a layer made of a polyolefin (B2) are laminated through a layer made of an adhesive resin composition (A). Using a coextrusion molding machine equipped with a plurality of extruders, a pellet of thermoplastic resin (a1) and a pellet of polyolefin (a2) are charged into one extruder, a pellet of another resin (B) is charged into another extruder, and A method for producing a multilayer structure according to any one of claims 1 to 5, characterized in that it is molded by an extrusion method. The method for producing a multilayer structure according to claim 6, wherein the pellets of the thermoplastic resin (a1) and the pellets of the polyolefin (a2) are previously dry blended and then fed into an extruder. The manufacturing method of the multilayer structure of Claim 6 or 7 whose extruder into which the pellet of thermoplastic resin (a1) and the pellet of polyolefin (a2) is thrown in is a single screw extruder. The manufacturing method of the multilayer structure of Claim 8 whose linear velocity of the screw outer periphery in a single screw extruder is 0.8-8 m / min.